1. Field of Invention
This invention relates to seatbelt systems and more particularly to seatbelt systems which automatically fasten a restraining belt about a passenger after he has seated himself.
2. Prior Art
Since seatbelt systems protect passengers by restraining them with a belt during vehicular emergencies, the passenger does not collide with dangerous objects and his safety is insured. However, for reasons such as the difficulty of fastening the restraining belt, etc., the proportion of wearers of seatbelts is very low.
For the above reason, seatbelt systems are presently proposed which can automatically fasten a restraining belt about the passenger after he has seated himself. In these seatbelt systems, a guide rail is provided on the vehicle body and a belt may be caused to approach or receed from a seated passenger by a slider, to which the outer end of a belt is fastened, which is able to move along the guide rail.
Among such seatbelt systems, the seatbelt system wherein a part of the guide rail at the rear of the vehicle is bent in a vertical direction and the guide path of the guide rail is basically vertical is preferred. Since the slider is prevented from moving forwards or backwards in a vehicular emergency by the rear part of the guide rail being vertical, the passenger may be brought into a secure belt fastened condition merely by the motion of the slider along the guide rail and the slider is prevented from moving forwards or backwards in the vehicle during vehicular emergenices without the provision of a special lock system and a complicated regulation system for the lock system.
With such a system, in a normal vehicular collision the slider is prevented from moving forward or backward in the vehicle by the guide rail and the passenger is maintained in a fastened condition. If the vehicle rolls over however, vertical forces may act on the slider to cause it to move along the vertical part of the guide rail and the restraint of the passenger will become uncertain. As a result, there is a possibility that the passenger's safety in such a vehicular emergency may be incomplete.